The Simulation Of The Tectonic Stress Field In Jinhu Depression

Jinhu depression is the main block of the oil and gas exploration and development in Jiangsu Oilfield. After the formation of the basin , the area has experienced series times of the tectonic activity, stress conditions are very complex and extremely rich in structural style. Gas and oil distribute mainly along the main fault and slope of the depression ,which like as bead, enriched in the broken nose and block formations which near the oil-generating depression. Now, with the increasing degree of exploration of the old liberated areas and the increasing difficulty of exploration, the room for the exploration of the main part of the construction decreased, Jinhu depression goes in to the fine exploration stage as the target of the complex and subtle reservoirs. Bring the hidden faults and block of the slope becomes the focus of future exploration, and relying on conventional means is difficult to detect the presence of these faults.Some research and practice has been indicated that structural stress is closely linked with the oil and gas distribution. Development and evolution of tectonic stress field not only control the formation of oil and gas basins and the formation & distribution of these structure within the basin, but also affects the development of the source rocks, reservoir and seal and the processes of the hydrocarbon generation, migration and accumulation. Therefore, taking the tectonic stress field simulation, analyzing the relationship of the distribution of the regional faults and stress field , It will have important significance for taking the research of the the hidden faults and guiding the oil and gas exploration.Based on the former research, Firstly, this paper summarizes the regional geology of the study area, clarified the background of the tectonic evolution of North Jiangsu Basin. Secondly, analyzed the Tectonic characteristics of the Jinhu depression , summarized the the distribution law of the fractures , and analyzed the main faults and tectonic evolution. analysis shows that the main fault has the characteristics of extension and strike-slip, the tectonic evolution of the depression can be divided into four stages; The main stress field of Wubu deposition is a north west extensional one. And that of the Sanduo deposition is right-lateral tension stress, which has a weak north-south extension. Yancheng deposition is effected by a vertical action, while there is a weak compression in the east-west direction .Based on this analysis, using the finite element method, this passage simulate the tectonic stress field of the Jin Lake by using ANSYS systematic simulation software. Then combine the simulation results with the current distribution of fracture, analysising the relationship between the stress and fracture distribution . Studies suggest that the low area of the maximum shear stress mainly distribute along the fault zone in the depression, Shearing mainly exist in the fault zone. the high value area of Stress intensity and the maximum principal stress, which consistent with the position of the major structural zone, is the favorable position for faults development...